abse/gameboy-advance

PCB_USER_NOTES.txt

PCB USER / PROTOTYPE BRING-UP NOTES

Battery connector pin 1 = positive, pin 2 = ground. Use four alkaline AA cells.
This board does not charge AA cells. Check holder wiring before connecting.
Begin with a current-limited bench supply and inspect for shorts first.
Confirm the3.234V logic rail and1.1V core supply voltages before connecting the display.
BOOTSEL selects USB boot mode; RUN resets the MCU. Ground/SWDIO/SWCLK/3V3
pads are for a compatible 3.3 V debug probe. Never apply 5 V to logic pins.
Speaker connector pin 1 = amplifier output plus; pin 2 = output minus.
Both speaker wires are driven: do not connect either to chassis/ground.
Use the specified8-ohm1W speaker. R_SPK_LIMIT provides passive attenuation;
check actual output, pops and maximum volume on the bench.
Insert the specified LCD flex with its contacts facing the connector contacts;
open its latch first. Disconnect power before inserting/removing the flex.
Check every button released and pressed before installing the enclosure.
A released switch must not short its GPIO to ground; pressing it must do so.
Firmware and USB/display qualification remain necessary before product use.

Pass the assembled JST PHR-2 battery plug through the rectangular PCB
opening before mating it to J_BAT. Protect leads from the milled edge and
provide cable slack/strain relief; do not force the plug through an old PCB.

Legacy V3V3/TP_3V3 names now denote the nominal3.234V logic rail.
See ELECTRICAL_PROTOTYPE_REVIEW.txt for the prototype load/ripple allowances.